The aim of the study was to investigate the changes in serum ceruloplasmin levels of ewes fed deficient-energy during late pregnancy. Thirty Chios ewes at 4-6 years of age were used in the study. On day 105 after random mating, the ewes were subjected to ultrasound examination to determine pregnancy. After that they were divided into three groups: Pregnant Normal Energy (PNE, n = 10), Pregnant Deficient Energy (PDE, n = 10) and Non-Pregnant Normal Energy (N-PNE, n = 10). From the mating day up to the day 105, all ewes were fed in according to the ration of N-PNE group. On day 106 of gestation, the animals were begun to be fed the treatment rations. Blood samples were taken from the jugular vein into the tubes before feeding in the morning on days 120, 127, 134, 141 and 148 during gestation. Serum ceruloplasmin levels were not statistically different between groups except day 148. On day 148, serum ceruloplasmin levels in the pregnant deficient group were significantly higher than in the other two groups (p<0.05). They were significantly higher in the pregnant normal energy group than in the non-pregnant normal energy group and were significantly lower in the pregnant normal energy group than in the pregnant deficient group (p<0.05). In the study, serum ceruloplasmin level became a sensitive indicator of feed deficiency in the last days of pregnancy. Thus, variations in this antioxidant in ewes with pregnancy toxemia may be of considerable clinical importance.